Adjusting Mechanism and Vehicle Seat

ABSTRACT

An adjusting mechanism includes a first sub-assembly, a bolt disposed on the first sub-assembly and a second sub-assembly. The bolt is configured to receive a force in a radial direction relative to an axis of the bolt. The second sub-assembly is mounted so as to be rotatable relative to the first sub-assembly by means of the bolt. The rotatability of the second sub-assembly relative to the first sub-assembly is configured to be reduced by a positive connection created using plastic deformation between the bolt and at least one of the first sub-assembly and the second sub-assembly.

DESCRIPTION

The invention relates to an adjusting mechanism, especially a mechanism for adjusting the inclination of the backrest of a vehicle seat, comprising a bolt which is disposed on a first sub-assembly and a second sub-assembly which is mounted so as to be rotatable by means of said bolt and to which a force (F) may be applied in a radial direction relative to the axis of rotation.

PRIOR ART

A generic adjusting mechanism is known from the publication DE 1,984,5698A 1. The mechanism for adjusting the inclination of the backrest of a vehicle seat described in this document consists of a first fixing plate connected to the backrest and a second fixing plate disposed on the seat part, which are rotatably connected to one another. A circular-arc-shaped peripheral region of the second fixing plate is provided with a toothed portion with which a latching pawl, which is rotatably mounted on the first fixing plate, may be brought into engagement. As a result of this engagement, which may be released for the adjustment, the angular position between the backrest and seat part may be fixed. A locking cam, also rotatably disposed by means of a bolt on the first fixing plate, prevents undesirable unlocking of the. latching pawl. Both in normal use, but especially under overload.due to an accident, a force acts on the bolt in a radial direction relative to the axis of rotation of the locking cam. In this connection, a structural load limit is preset, up to which the clamping force of the locking cam is maintained and thus the backrest remains fixed in its set position.

OBJECT

The object of the invention is to improve the safety of a generic adjusting mechanism at low cost.

SOLUTION

The object is achieved according to the invention in that, with a generic mechanism, the rotatability of the second sub-assembly relative to the first sub-assembly may be reduced with the aid of a positive connection between the bolt and the first sub-assembly and/or the second sub-assembly, which may be created using plastic deformation. The overload due to an accident, which essentially attempts to unlock the adjusting mechanism, thus simultaneously initiates (irreversible) means which counteract this unlocking.

The bolt may, in this case, be connected fixedly in terms of rotation to the first sub-assembly, and the positive connection being able to be created between the bolt and the second sub-assembly. Alternatively, it is conceivable to connect the bolt fixedly in terms of rotation to the second sub-assembly and to create the positive connection between the bolt and the first sub-assembly.

The positive connection is preferably able to be created by the bolt being rotatably mounted in a hole, which is at least partially toothed on its inner circumference, in the first or second sub-assembly. In this connection, the inner circumference of the hole advantageously has, at least in the region of the toothed portion, a greater hardness than the outer circumference of the bolt. When the overload occurs, the teeth dig into the bolt and prevent the rotation thereof relative to the hole. Under normal working load, however, the rotational movement is uninterrupted. Moreover, it is possible in principle, to unlock the adjusting mechanism again after the overload has subsided, for example to allow vehicle passengers to leave the vehicle by folding forward the backrest.

The toothed portion is preferably disposed in a segment of the inner circumference of the hole, the force application point of the force F under overload being disposed approximately centrally on the circular arc thereof. In this connection, the toothed segment extends on either side of the force application point, advantageously over an angle of less than 45°, preferably approximately 30°. In this angular range, the toothed portion deploys its greatest effect.

According to a preferred embodiment of the invention, the adjusting mechanism is a locking mechanism for adjusting the inclination of the backrest of a motor vehicle seat, the first sub-assembly being a first fixing plate connected to the backrest and the second sub-assembly being a locking cam, by means of which a latching pawl rotatably mounted on the first fixing plate may be held in engagement with the toothed portion of a second fixing plate which may be pivoted relative to the first fixing plate.

FIGURES

The figures show by way of example and schematically an embodiment of the invention, in which:

FIG. 1 is a side view of a mechanism for adjusting the inclination according to the invention,

FIG. 2 is an enlarged view of the locking cam of the mechanism for adjusting the inclination according to FIG. 1,

FIG. 3 is a further enlarged illustration of the toothed portion in the locking cam of FIGS. 1 and 2.

The adjusting mechanism 1 consists of a first fixing plate 2 for attaching to the backrest, not shown, as well as a second fixing plate 3 for fixing to the seat part of the vehicle seat, also not shown. The second fixing plate 3 is partially provided on its outer periphery with a toothed portion 4. A latching pawl 5, which, with a counter toothed portion 6, may be brought into positive engagement with the toothed portion 4, is rotatably disposed on the first fixing plate 2 (first sub-assembly). The locking in the locked position, as well as the unlocking, of the latching pawl 5 are carried out by a locking cam 7 (second sub-assembly) which is pivotably mounted on a rigid bolt 8 projecting from the first fixing plate 2. The locking cam 7 is driven by a toothed member 9. With regard to the function of such adjusting mechanisms, reference is made expressly to the aforementioned publication DE 1,984,5698 A1, and with regard to the configuration of the toothed member 9, reference is made to the, as yet unpublished, patent application DE 1,031,2136.6-16.

During normal use, especially however under overload due to an accident, a force F, which is diverted into the first fixing plate 2 via the bolt 8, is already applied to the locking cam 7, shown enlarged in FIG. 2, in a radial direction relative to the axis of rotation 10 of the locking cam 7. The hole 11 inserted into the locking cam 7, into which the bolt 8 is pushed, is provided with a toothed portion 13 in a segment 12 of its inner circumference. The segment 12 extends on either side of the direction of the force application point 14 in the transition between the bolt 8 and the locking cam 7 over an angle α of respectively 30°.

As is visible from FIG. 3, the individual teeth 15 are formed by recesses 16 on the other side of the inner circumference of the hole 11, i.e. not projecting therein. Thus, during normal use, the rotatability of the locking cam 7 on the bolt 8 is not hindered. If, however, the radial force F exceeds a normal amount, the relatively hard teeth 15 dig into the outer circumference of the relatively soft bolt 8 and act against a rotation of the locking cam 7 by means of a positive connection. Undesirable unlocking of the system is counteracted thereby.

Reference Numerals

-   1 Adjusting mechanism -   2, 3 Fixing plate -   4 Toothed portion -   5 Latching pawl -   6 Counter toothed portion -   7 Locking cam -   8 Bolt -   9 Toothed member -   10 Axis of rotation -   11 Hole -   12 Segment -   13 Toothed portion -   14 Force application point -   15 Teeth -   16 Recess 

1. An adjusting mechanism comprising: a first sub-assembly; a bolt disposed on the first sub-assembly to receive a force in a radial direction relative to an axis of the bolt, and a second sub-assembly rotatable relative to the first sub-assembly via the bolt, wherein rotation of the second sub-assembly relative to the first sub-assembly is reduced by a positive connection between the bolt and at least one of the first sub-assembly and the second sub-assembly,
 2. The adjusting mechanism of claim 1 wherein the bolt is connected fixedly in terms of rotation to the first sub-assembly and the positive connection is created between the bolt and the second sub-assembly.
 3. The adjusting mechanism of claim I wherein the bolt is connected fixedly in terms of rotation to the second sub-assembly and the positive connection is created between the bolt and the first sub-assembly.
 4. The adjusting mechanism the bolt is rotatably mounted in a hole defined by one of the first sub-assembly and the second sub-assembly, an inner circumference of the hole being at least partially toothed.
 5. The adjusting mechanism of claim 4 wherein the inner circumference of the hole has, at least in the region of the toothed portion, a greater hardness than an outer circumference of the bolt.
 6. The adjusting mechanism of claim 5 wherein the toothed portion is disposed in a segment of the inner circumference of the hole, a force application point of the force under overload being disposed approximately centrally on the circular arc of the segment.
 7. The adjusting mechanism of claim 6 wherein the toothed segment extends on either side of the force application point of the force over an angle of less than 45° 8-9. (canceled)
 10. The adjusting mechanism of claim 7 wherein the toothed segment extends on either side of the force application point of the force over an angle of approximately 30°.
 11. The adjusting mechanism of claim 1 wherein the positive connection results from plastic deformation of the bolt relative to one of the first sub-assembly and the second sub-assembly.
 12. A recliner mechanism for adjusting the inclination of a backrest of a vehicle seat relative to a seat part, the recliner mechanism comprising: a first fixing plate configured to be connected to the backrest; a second fixing plate configured to be connected to the seat part and having a toothed portion, the first fixing plate being rotatable relative to the second fixing plate; a latching pawl rotatably mounted on the first fixing plate and configured to engage the toothed portion of the second fixing plate for locking the first fixing plate relative to the second fixing plate; a bolt connected fixedly in terms of rotation to the first fixing plate; and a locking cam rotatably supported by the bolt for holding the latching pawl in engagement with the toothed portion, wherein, when a load applies a predetermined radial force to the locking cam, rotation of the locking cam relative to the first fixing plate is reduced by a positive connection between the bolt and the locking cam, and wherein the positive connection is created by plastic deformation of one of the bolt and the locking cam against the other of the bolt and the locking cam.
 13. The recliner mechanism of claim 12 wherein the locking cam includes an inner circumference defining a hole configured to receive the bolt, the inner circumference having a toothed portion.
 14. The recliner mechanism of claim 13 wherein the toothed portion of the inner circumference has a greater hardness than an outer circumference of the bolt.
 15. The recliner mechanism of claim 14 wherein the toothed portion of the inner circumference digs into the outer circumference of the bolt to provide the positive connection created using plastic deformation.
 16. The recliner mechanism of claim 15 wherein the toothed portion of the inner circumference is limited to a segment of the inner circumference.
 17. The recliner mechanism of claim 16 wherein the segment extends on both sides of an application point of the radial force over an angle of less than 45°.
 18. The recliner mechanism of claim 17 wherein the segment extends on both sides of the application point over an angle of approximately 30°.
 19. A vehicle seat comprising: a backrest and a seat part; a recliner mechanism for adjusting the inclination of the backrest relative to the seat part, the recliner mechanism comprising: a first fixing plate connected to the backrest; a second fixing plate connected to the seat part; a latching pawl rotatably mounted on the first fixing plate and configured to engage the second fixing plate for locking the first fixing plate relative to the second fixing plate; a bolt connected fixedly in terms of rotation to the first fixing plate; and a locking cam rotatably supported by the bolt for holding the latching pawl in engagement with the second fixing plate, wherein a positive connection created using plastic deformation between the bolt and the locking cam reduces the rotatability of the locking cam relative to the bolt when an overload force is applied in a radial direction relative to an axis of rotation of the locking cam.
 20. The vehicle seat of claim 19 wherein the locking cam includes an inner circumference defining a hole configured to receive the bolt, the inner circumference having a toothed portion that has a greater hardness than an outer circumference of the bolt.
 21. The vehicle seat of claim 20 wherein the toothed portion of the inner circumference digs into the outer circumference of the bolt to provide the positive connection created using plastic deformation.
 22. The vehicle seat of claim 21 wherein the toothed portion of the inner circumference is limited to a segment of the inner circumference.
 23. The vehicle seat of claim 22 wherein the segment extends on both sides of an application point of the radial force over an angle of less than 45°.
 24. A vehicle seat comprising: a backrest and a seat part; a recliner mechanism for adjusting the inclination of the backrest relative to the seat part, the recliner mechanism comprising: first and second sub-assemblies that move relative to one another during recline of the backrest relative to the seat part; a bolt that connects the first sub-assembly to the second sub-assembly and that is configured to receive a force in a radial direction relative to an axis of the bolt wherein, when the force reaches a predetermined value, movement of the first sub-assembly relative to the second sub-assembly is restricted by a positive connection between the bolt and one of the first and second sub-assemblies due to plastic deformation of the bolt against one of the first and second sub-assemblies.
 25. The vehicle seat of claim 24 wherein the first sub-assembly is a first fixing plate connected to the backrest and the second sub-assembly is a locking cam configured to hold a latching pawl in engagement with a second fixing plate connected to the seat part. 